This invention relates to a fitting structure of a waterproof plug for sealing a gap between a terminal insertion hole in a waterproof connector and a wire extending from a terminal inserted in the terminal insertion hole.
FIG. 3 shows a related waterproof connector analogous to a connector disclosed in Japanese Patent Publication No. 9-106852A. This waterproof connector comprises a connector housing 1 formed with a plurality of terminal insertion holes 2. Terminals 3, each connected to a distal end of a wire 10, are inserted in the terminal insertion holes 2, respectively.
A rubber plug (waterproof plug) 7 is fit with an outer peripheral face of the wire 10 extending rearwardly from the terminal 3. When the terminal 3 is inserted in the terminal insertion hole 2 in the connector housing 1, the rubber plug 7 is held in intimate contact with the inner peripheral face of the terminal insertion hole 2, thereby sealing a gap between the wire 10 and the terminal insertion hole 2. In this case, the rubber plug 7 is clamped over the wire by wire clamping pieces 4 formed at a rear end of the terminal 3.
FIG. 4 shows details of the fitting structure of the rubber plug 7.
Core clamping pieces 5 for electrical connection to a core wire 12 of the wire 10 are formed at the rear end portion of the terminal 3, and also the wire clamping pieces 4 for clamping a sheath 11 of the wire 10 are formed at the rear end portion of the terminal 3. In the related construction, a leading end portion 7a of the rubber plug 7, fit on the outer peripheral face of the sheath 11, is clamped by the wire clamping pieces 4 simultaneously when clamping the sheath 11 of the wire 10 by the wire clamping pieces 4. Namely, the leading end portion 7a of the rubber plug 7 is fit on the outer peripheral face of the sheath 11 of the wire, and then the wire clamping pieces 4 are bent inwardly to embrace this portion, thereby clamping the rubber plug 7 and the sheath 11 together.
In the above fitting structure of the rubber plug 7, the leading end portion 7a of the rubber plug 7 is fit on the sheath 11 of the wire 10, and in this condition, the wire clamping pieces 4 are pressed or deformed to embrace this portion. Therefore, a diameter d1 of this clamped portion 8 has enlarged.
A diameter D1 of each terminal insertion hole 2, shown in FIG. 3, need to be larger than the diameter d1 of the clamped portion 8 of the rubber plug 7 since the clamped portion 8 is to be inserted into the terminal insertion hole 2 as shown in FIG. 5. Therefore, when the diameter d1 of the clamped portion 8 increases by an amount corresponding to the thickness t of the sheath 11 of the wire 10, the diameter D1 of the terminal insertion hole 2 correspondingly increases. As a result, there has been encountered a problem that the pitch P1 of the terminal insertion holes 2 increases, so that the size of the waterproof connector is enlarged.